Japanese Laid-Open Patent Publication No. 7-298596 discloses a three-phase brushless motor. The motor of the above publication includes a cylindrical stator with a plurality of teeth. The teeth project radially inward from the inner circumferential surface of the stator and are arranged at equal intervals in the circumferential direction. A wire is wound about the teeth, so that coils of three-phases are formed. A rotor (mover), which is rotatable relative to the stator, is located radially inward of the stator. The rotor has permanent magnets that create field poles. The excitation coils of respective phases each receive an alternating-current of which the phase is displaced by 120° relative to the phases of the alternating-current power supplied to the coils of the other two phases. When the alternate-currents supplied to the excitation coils magnetizes the teeth to which the coils are attached, repelling and attracting forces are repeatedly generated between the teeth and the permanent magnets of the rotor. This in turn rotates the rotor.
Winding wires about teeth is burdensome. Particularly, in an electric motor having teeth projecting radially inward from the inner circumferential surface of the stator, the space between adjacent teeth narrows toward the radially inner ends. Thus, wires are difficult to wind about the teeth. This lowers the workability when the motor is manufactured.